This invention relates to an under-floor unloading system for unloading the crops from a storage bin of a type which can be used for crops or other dry solid flowable materials.
The storage of crop material is generally carried out in a storage bin which includes a vertical usually cylindrical wall mostly including a conical roof covering the top edge of the wall. The bin is generally mounted on a horizontal concrete pad or other suitable base to provide a proper support for the wall and so as to ensure that the crop material is supported on a suitable generally smooth surface from which it can be removed.
Various techniques have been proposed for emptying the grain bin. Conventionally an auger is inserted into the bin so as to extract the material and this discharges of the majority of the material without difficulty. However, the material adjacent the floor remains in place and must be discharged to allow complete emptying of the bin. For many years this was done by shovelling.
Some bins are currently mounted on conical hopper bottoms which discharge the material to a central discharge opening but these bottom structures raise the bin wall thus making the whole structure less stable and reducing the amount of material which can be contained.
In U.S. Pat. No. 4,029,219 (Rutten) assigned to P and D manufacturing discloses an under floor discharge system which includes a horizontal auger tube laid in a channel in the concrete base. The base therefore must be thicker to accommodate the tube which remains in place at all times. The auger flight is separate element which is inserted in to the tube when required and can be removed for use of the bins when necessary. The tube is filled from a central opening and the remaining material can be swept to the central opening by a rotating bin sweep.
This arrangement has the disadvantages that the concrete pad must be increased in thickness thus increasing cost, an additional auger structure is necessary for transporting material through the tube in the concrete which again increases the cost, and it is in many cases difficult to transport the bin sweep into the interior of the bin after an initial quantity of crop material is discharged since the crop material remains at a significant depth at the wall due to the angle of repose of the crop material.
U.S. Pat. No. 5,511,925 (Muth) issued Apr. 30, 1996 discloses a similar discharge system but in this case the discharge auger is mounted above floor level so that the sweep rotates underneath the discharge auger system. This arrangement has a significant disadvantage that it is relatively costly in order to provide the auger construction. The discharge auger has openings in the top surface storage to allow the entry of crop material both adjacent the center and the closer to the wall.
U.S. Pat. No. 5,318,444 (Kuzub et al) issued Jun. 7, 1994 discloses a discharge device in the form of a small dedicated auger which is inserted through a door in the wall of the bin and incline downwardly toward the center of the bin and carries its own bin sweep which rotates around the bottom of the discharge auger.
Again this constructions relatively expensive in view of the dedicated cost of the device.
It is one object of the present invention, therefore, to provide an improved bin for storage of dry flowable materials which is designed and arranged to allow easy ergonomic extraction of the material using a conventional discharge auger.
According to a first aspect of the invention there is provided a storage bin comprising:
a substantially horizontal floor pad defining a pad surface;
a bin wall arrangement mounted on the pad so as to stand upwardly therefrom and to define with the pad surface a container for a crop material;
a pit arranged below the pad surface into which crop material can fall from the container;
the pit having at least one container opening therefrom into the container, the at least one container opening having a door operable to be moveable from a closed position preventing discharge of material from the container through the opening into the pit to an open position allowing discharge of the material into the pit by gravity to a bottom of the pit below the container opening;
the pit having an exterior opening outside the container;
the pit being shaped for co-operation with an auger standing outside the container with an inclined auger tube extending downwardly from a top discharge end of the auger to a bottom feed end of the auger such that a bottom feed end portion of the auger can be inserted into the pit through the exterior opening and extend to the bottom of the pit for extracting the material falling into the pit through the container opening.
Preferably the bottom of the pit is below the exterior opening.
Preferably the bottom wall of the pit is inclined downwardly from the exterior opening to the bottom of the pit at an angle approximately equal to the angle of incline of the auger.
Preferably the pit is generally triangular in side elevational shape with a bottom apex such that a second bottom wall portion is inclined from the container opening downwardly and along the pit toward the exterior opening.
Preferably the exterior opening is generally horizontal.
Preferably the at least one container opening includes a first opening adjacent a center of the container and a second opening spaced along the pit adjacent the wall.
Preferably each of the first and second container openings includes a respective door separately operable to open and close the opening.
Preferably the wall includes an inlet door adjacent the second opening for insertion into the bin of a bin sweep.
Preferably the pit is covered between the first and second openings by a removable cover plate.
Preferably the removable cover plate is perforated to allow passage of air from the pit into the crop material.
Preferably the pit includes a removable hopper at a bottom apex for extraction of remaining crop material.
According to a second aspect of the invention there is provided a method for unloading crop material from a storage bin comprising:
providing a crop storage bin comprising:
a substantially horizontal floor pad defining a pad surface;
and a bin wall arrangement mounted on the pad so as to stand upwardly therefrom and to define with the pad surface a container for a crop material;
providing a pit arranged below the pad surface into which crop material can fall from the container;
providing at least one container opening from the container into the pit;
opening a door from a closed position preventing discharge of material from the container through the opening into the pit to an open position allowing discharge of the material into the pit by gravity to a bottom of the pit below the container opening;
providing for the pit an exterior opening outside the container;
providing an auger standing outside the container with an inclined auger tube extending downwardly from a top discharge end of the auger to a bottom feed end of the auger;
and inserting the inclined bottom feed end portion of the auger into the pit through the exterior opening so as to extend to the bottom of the pit for extracting the material falling into the pit through the container opening.